MRI Research Highlights Brain Structure Differences in Children with Restrictive Eating Disorders

Recent MRI studies have shed light on the distinct brain changes associated with restrictive eating disorders in children, such as anorexia nervosa and avoidant/restrictive food intake disorder (ARFID). Over the past decade, cases of these disorders in children have doubled, leading to serious health concerns including nutritional deficiencies, delayed bone growth, and issues with puberty. Despite extensive research on adults, little was understood about how these disorders impact the developing brains of children.

To explore this, researcher Clara Moreau and her team conducted MRI scans on 290 children below 13 years old. Among them, 124 were hospitalized with early-onset anorexia nervosa (EO-AN), 50 with ARFID, and 116 children served as controls without eating disorders. The children with EO-AN exhibited significantly lower body mass indexes (BMI) due to restrictive eating, while those with ARFID also had low BMI but showed different brain characteristics.

EO-AN is typically driven by distorted body image, leading to restrictive eating behaviors. In contrast, ARFID stems from sensory sensitivities, such as dislike of certain textures, disinterest in food, or fear of negative health outcomes—all of which suggest different underlying brain mechanisms.

Findings revealed that children with EO-AN experienced widespread cortical thinning, a reduction in the brain's outer layer, and increased cerebrospinal fluid compared to children without eating disorders and those with ARFID. Additionally, there was a notable correlation between BMI and cortical thickness in specific brain regions. Conversely, children with ARFID displayed reduced surface area and overall brain volume, with no direct link to BMI. Both groups had lower gray matter volume than typical children, but the structural brain changes differed markedly between the two disorders.

Further comparison with children suffering from ADHD, OCD, and autism uncovered similarities between EO-AN and OCD, as well as ARFID and autism, indicating shared brain features. Surprisingly, no significant similarities were found between these eating disorders and ADHD, despite some clinical observations linking ARFID and ADHD. This is an important step in differentiating the neurobiological basis of these conditions.

This large-scale MRI study provides valuable insights into the neurobiological differences underlying early-onset restrictive eating disorders. Understanding these distinctions helps clarify how each disorder develops and relates to other mental health conditions. Such knowledge is essential for developing targeted treatments and prevention strategies.

However, the research highlights the need for further studies to address limitations like the relatively small ARFID sample size and to investigate brain recovery processes post-weight restoration. Continued research will improve our ability to treat and potentially prevent these disorders in children.